1. Field
Example embodiments relate to a data receiver circuit and a method of adaptively controlling equalization coefficients using the same.
2. Description of Related Art
In general, the frequency spectrum of a signal may be degraded when the signal transfers through a transmission medium, such as a cable. Typically, the degradation may lead to attenuation of a high-frequency component in the frequency spectrum of the signal. Due to the frequency degradation, the transferred signal may have a narrow signal pulse which has a low peak amplitude. As a result, it may be difficult to recover encoded bit information of the signal pulse. Also, a signal applied to a receiver through the transmission medium may include a jitter noise. Similarly, it may be difficult to recover the signal including the jitter noise. To compensate for the frequency degradation, a signal processing process called an equalization process may be performed. The equalization process refers to a technique of decreasing the jitter noise of the applied signal and restoring the amplitude of the attenuated frequency component to the previous amplitude.
In a transceiver mainly used for an ultrahigh-speed serial interface, the transmission rate of serial data is gradually increasing to several Gbps or higher. Thus, with the increase in the transmission rate of the data, jitter noise of the receiver may significantly affect a process of recovering clock or data without errors in a clock and data recovery (CDR) block. The jitter noise may occur by inter-symbol interference (ISI) on signals received at through the interface. When a long cable or a printed circuit board (PCB) routing is used as a main medium, the ISI may increase. An equalizer may be added to the receiver to decrease inter-symbol interference (ISI).